Kern: A Production-Grade Structured Python Logger (Beats Stdlib/Loguru/Structlog)

TL;DR: New Python logger (Kern) aimed at production ops.

Logging isn’t free — it burns CPU, memory, and sometimes even infra $$$. So I built Kern, a structured logger focused on production ops, not dev sugar.

Benchmarks (1 thread, 5k logs each):

Info throughput: Kern ~84k logs/s (stdlib ~77k, structlog ~61k, loguru ~31k)

Memory: Kern ~38 MB steady (stdlib ~32 MB, structlog ~52 MB, loguru ~83 MB under exceptions)

Exceptions: slower than structlog, but structured & bounded (same cost as stdlib, richer payloads)

At scale, efficiency like this can mean $100k+/year infra savings.

Why this isn’t “yet another wrapper”

Feature comparison (Kern vs ecosystem)

Strict JSON, ISO8601, schema versioning

Contextvars propagation (trace/span IDs auto)

Async TCP/TLS streaming with backoff/jitter

Hot-reload log levels from K8s/JSON

Observability of the logger itself (emitted, dropped, queue depth, backoff, last error)

Competitors (Loguru, Structlog, Eliot, Logbook, Picologging, stdlib) each win in their niche (ergonomics, C-speed, causal tracing) — but none combine speed + enterprise readiness.